#include <iostream>
struct Student{
    char num[10];
    char name[8];
    int score[3];
    float aver;
} stu[5];
int main() {
    int i, j, sum;
    FILE * fp;
    for(i = 0; i < 5; i++) {
        printf("\ninput score of student %d\n", i+1);
        printf("NO.:");
        scanf("%s", stu[i].num);
        printf("name:");
        scanf("%s", stu[i].name);
        sum = 0;
        for (j = 0; j < 3; j++) {
            printf("score %d:", j + 1);
            scanf("%d", &stu[i].score[j]);
            sum += stu[i].score[j];
        }
        stu[i].aver = sum / 3.0;
    }
    fp = fopen("D:\\C\\stud", "w");
    for (i = 0; i < 5; i++) {
        if (fwrite(&stu[i], sizeof(struct Student), 1, fp) != 1)
            printf("file write error!!!\n");
    }
    fclose(fp);
    fp = fopen("D:\\C\\stud", "r");
    for (i = 0; i < 5; i++) {
        fread(&stu[i], sizeof(struct Student), 1, fp);
        printf("\n%s,%s,%d,%d,%d,%6.2f\n", stu[i].num, stu[i].name, stu[i].score[0],
               stu[i].score[1], stu[i].score[2], stu[i].aver);
    }
    return 0;
}
